Python

What did you do with indexes in PostgreSQL that helped reduce latency (p95/p99)?

Have you worked with context managers? If I have my class and I want it to be a context manager, what should I do?

I wrote the same function with calculations in C++ and Python, ran it in multithreading. Fast in C++, slower in Python. Why?

How can we influence what the model's response will be?

If the offset has already been moved, and the message processing service has failed and lost it — what can be done?

What happens to the strings that are deleted from the database, and what happens to the index after data is deleted?

Tell me about Kafka: why is it needed, what is it usually used for?

We found a service that performs an INSERT into this table. After adding a unique constraint, the service started failing with an error. Can we modify the SQL query so that it does not fail when the unique constraint is triggered, without changing the application logic?

If I work with asynchronous code, how to implement a context manager?

Is the complexity of adding to a dictionary O(1) always true, or are there situations when it is not?

What are tools (tool calling) in an agent?

What is MCP and how is it related to tool calling?

How does a transaction work? What happens during BEGIN and COMMIT?

Can a body be added to a GET request? What will happen then?

What types of HTTP methods (endpoints) do you know in REST API?

What are hallucinations in LLMs and how to deal with them?

What architecture is needed for an internet store support agent if all the infrastructure (chat, backend) is already ready?

We have a table with a primary key of type INT. The table will soon overflow and INT will be exhausted. We need to change the primary key type from INT to BIGINT. What steps would you take to change the primary key column type?

We understood that we do not have an index, so we created an index. In what situations might this index not work?

How are Python variables stored in RAM?